FIG. 1 shows, in a schematic manner, a typical onshore hydrocarbon well location and surface equipment SE above a hydrocarbon geological formation GF after a well-bore WB drilling operation has been carried out, after a casing string has been run, after cementing operations have been carried out and after various logging operations for detecting interesting zones have been carried out.
At this stage, i.e. before exploitation can begin, the cemented casing CC must be perforated so that a selected zone SZ of the formation is put into communication with the well-bore WB. Accordingly, a perforating gun 1 suspended on line LN is lowered at a determined depth. Typically, such a perforating gun 1 loaded with many/various charges, e.g. shaped charge SC, is disclosed in the document US 2002/0189482. The detonation of the charges creates perforation, namely openings into the cemented casing continuing by a tunnel into the formation, thus allowing the fluid contained in the selected zone to enter into the well casing or the fluid pumped from the surface to be injected into the selected zone. However, during the perforation operation, the material of the shaped charge may clog the perforation. For example, the molten plastic liner may recover the interior of the perforation. As a consequence, the flow of fluid through the perforation may be hampered. Though various liners have been proposed in the past in order to avoid, or at least limit the effect of clogging, they are still not entirely satisfactory in the oilfield applications.